J Chen

Hi Edman,
How's the going ? Just wanted to thank you
for the tips & advice regarding the GT turbo
install. Finally got my GT25 installed. I had
alot more mods than your install. Will post
pics the minute I learn how to shrink it down
to size.

Thanks again

Indica

Does your car run with the GT25 yet? I am dying to hear how fast one of those can spool. I am thinking about replacing my k27 with a GT25. Care to share the specs on the turbo? AR's, inlet size, compresser wheel?

J Chen

Hi Indica,
It's a GT25TO4S with a .86 turbine housing.
It's rated at 440 hp. The compressor wheel
is standard issue. I'm very confident that it will
spool just like a K26/6 if not faster.
Theres alot of work involved as the compressor
housing is huge. Meaning many custom parts
needed. I'm not sure if the effort I've put in is
worth while but at least I learn alot & as a
consolation, I think I'm the only one in exsistance
running this turbo. I'm sure that the set-up that
Technodyne is selling does not use the TO4S
housing.

Edman951

Congatulations J Chen,
Happy to hear you project is finished.
Happy to have been helpfull.

Did you drive it yet?
How does it go?
Please post picture and info about you setup.
And the things you had to do to install it.
What did you do for the mount, and the x-overpipe?
How hard was it to fit the T04S housing under the manifold.

Can't wait to see pictures.
If you need a place to host your picture's, check out this place.
http://forum.vwsport.com/portal.php
Or click directly here
http://sites.vwsport.com/shp.php
I use this place to host small video.

The first GT2540R to J Chen.

J Chen

Hi Edman,
Thanks again. I used the same set up like you for
the mount but I welded the flange to the NPT adaptor.
Due to the size of the TO4S, I had to cut down the
engine mount alot more. I also had to replace the
alternator to a 90 amp unit for clearance reasons.
Firing up the engine tommorrow. Will try to post
pics a.s.a.p

Edman951

Cool, good luck with the start up tomorrow.

Indica

J Chen,
Great job on the install! Why did you go with the larger AR on the turbine? I was thinking about going with the .64ar- should make for a fun (fast spooling) street car setup. How big is the inlet on the to4s housing? Can you get the GT25 with any housing- like to4e- or 60-1hifi- or 60-1 with 4" inlet? Is there a list of housings availible anywhere? I did not know that you could get housings other than 60-1 like this one: http://www.atpturbo.com/Merchant2/me...egory_Code=GRT

Does the 5 bolt exit flange bolt up to the downpipe like th gt30 does?
I look forward to seeing your pics. Also very interested in hearing your impression of the turbo!

Edman951

From what i know, that the exact turbo he got.
Also the .64a/r is pretty small for our car. It's even considered restrictive for a 300hp nissan SR20DET witch is a 2.0L 16V.
I'm sure the .84 will spool great.

Indica

I must be confused it says on the description:
" Large 60- 1 style compressor housing with 4.00" inlet and 2.50" outlet. Very Good response turbo for 4 Cyl applications. This turbo has a flow capacity of about 450HP."

You are probally right- i dont have a GT turbo yet. I just have been planning to do my own since I saw your gt30 instal posted on Rennlist. Thanks for the tip about the ar. I will keep that in mind when the time comes to purchase the turbo. Any idea where I can find a list of the different compresser housings you can use with the gt25?

Edman951

A T04S is a Large 60- 1 style compressor housing.

There are note many housing you can use on a gt25.
The only 2 i know of are the T25 and the T04S used on the GT2540R. (40=T4s)
A normal GT25 is simular in size to a K26/6 but the k26 out flows it. So you want to go bigger if you want to gain power. A GT2540R is about the smallest to go with if you want to get more power out of your 951.
Only J Chen will be able to answer the power potential of the GT2540R.
Can't wait to hear about it.

J Chen

Hi Indica,
Edman is correct. In reality the AR nos is very deceiving.
You would have to compare the actual model of the turbo
that you're buying to get an idea. As for the GT 25, the
.86 AR is only marginally larger than a K26/6 which
should make it a good one for 2.5L with quick spool.
Personally, I would hope to see full boost by 2800rpm
with something like 350 rwhp at 18 psi.
As for the compressor housing, It comes standard with
the TO4S. Be warn that going to a different housing will
change the performance of the turbo especially during
the initial on boost period. Overall flow will not be affected
though. It's similar to changing a cam. You move the torque
band higher up in the rev range.

J Chen

Thanks Edman for the encouragement.

Edman951

You're welcome
Lets go J Chen, lets go... clap clap clap....

Indica

Thank you for the good info!
Full boost a 2800 and 350hp sounds like a very sweet setup! I hope you get your desired results. For me that would be the ultimate street 951! fast spool- lots of power! Keep us posted J- Chen!

J Chen

Thanks Guys